Continuous catalyst regeneration (CCR) naphtha processes are designed to operate at high severity of low pressure, low hydrogen to carbon ratio and produce high octane reformates for gasoline blending. The desired operating range to sustain steady state white burn regenerator operations for good unit productivity requires that the process generates catalyst coke in a range of 3.0 to 7.0 wt. %. Recent environmental regulations have led to a need to operate and produce low octane reformates due to substantial ethanol blending. In the past the concentration of ethanol in a gasoline blend was 10 vol. %. Recently an increase to 15 vol. % for cars manufactured after 2007 has been proposed.
Due to the need to minimize expensive gasoline octane give away, refiners are now operating their CCR reformers at low severities which lead to catalyst coke production rates that are lower than 3 wt. %. Due to considerations of catalyst flow and sustaining steady state coke burns, refiners are opting to shutting down their regenerators for long periods of time in order to not damage equipment such as air heaters, disengaging hopper and the regenerator screens. The frequent regenerator outages lead to poor catalyst performance, low unit productivity and uneconomical operative reformer operations.